The arrangement of one current transformer each on both sides of an interrupter unit makes possible the calculation of the current differentials and consequently the determination of possible ground faults in the area of the interrupter unit.
German Unexamined Patent No. 18 10 405 describes an enclosure housing connected to ground potential, including a high-voltage switch and current transformers arranged to both sides.
In outdoor switches, outdoor circuit breakers in particular, current transformers are usually installed separate from the switches in a separate enclosure. This requires a high degree of complexity, resulting in high costs.
A high-voltage outdoor switch according to the precharacterizing portion of claim 1 is known from European Patent No. 0 237 776 A2 in which the current transformers are mounted on the outside of the switch enclosure. This makes a separate housing for the current transformer necessary and represents a high assembly expense.
The object of the present invention is therefore to devise a means of monitoring the working order of a high-voltage outdoor switch by current transformers which is of simple design and is cost-effective.
According to the present invention, the objective is attained by the fact that at least one of the current transformers is arranged in the gas compartment of the interrupter unit.
In this way, the current converters can be cost-effectively integrated into the enclosure of the high-voltage switch and neither of the current transformers is required to be installed separately. In a particularly favorable form, low-power transformers, optical current transformers or surface wave elements can be used in this manner.
An advantageous embodiment of the invention provides that the high-voltage outdoor switch has the form of an erect pole column with current transformers arranged above and beneath the interrupter unit.
This is a space-saving and easily installed type of construction of the high-voltage switch according to the present invention.
Advantageously, the measuring signals of the current transformer connected to high voltage is conducted to ground potential via optical waveguide. This avoids having to route an electrical conductor from high voltage to ground potential. For the case in which the current transformer does not emit any measured values in the form of electrical signals, an electro-optical transducer is provided in the area of the current transformer. The electro-optical transducer can be supplied with power by tapping power from the magnetic field of the primary current or by the supply of power in the form of electromagnetic radiation, particularly via an optical waveguide. The converter can be located both within as well as outside the gas compartment of the interrupter unit.
The optical waveguide can be particularly advantageously integrated into the insulating enclosure of the high-voltage switch.
This can, for instance, be brought about by producing the insulating enclosure from a material into which the optical waveguide can be cast such as fiber-reinforced plastic, for instance.
In addition, it can be advantageously provided that at least one capacitive voltage transformer is integrated into the enclosure of a current transformer.
In this manner, all the necessary measuring devices for the monitoring of a high-voltage outdoor switch are combined in one single constructional unit.
An additional advantageous embodiment of the invention provides that the enclosure is at least partially designed as a composite insulator, made particularly of fiber-reinforced plastic.